The Reagan Diaries is the latest from the prolific Brinkley, who in July joins the history department at Rice University. The 767-page Diaries represents a substantial selection from the daily record Ronald Reagan kept during his White House years. Brinkley was selected to edit it after his 2005 book about the D-Day assault on Pointe du Hoc, France, won the admiration of former California Gov. Pete Wilson and Nancy Reagan. Mrs. Reagan, who's custodian of the diaries, had the final say.

Brinkley, who will sign The Reagan Diaries at Brazos Bookstoretoday, discussed the book with Chronicle books editor Fritz Lanham.

Q. What are some of the things you learned about Ronald Reagan that you didn't know, some of the things that surprised you?

A. I always knew he was a conservative, but I learned more and more that he was a pragmatic conservative. He had a firm vision of where he wanted to lead the country in regard to fighting communism and cutting taxes, among other things. But he was highly practical in achieving results, meaning he was always willing to compromise with Democrats and negotiate with adversaries.

You see the man who calls the Soviet Union the Evil Empire and says, "Mr. Gorbachev, tear down this wall," working constantly behind the scenes to try to get sweeping arms reductions with that same adversary. It's across the board. He's very close to Tip O'Neill and Ted Kennedy and personally likes them. He holds no malice toward his adversaries. The only person he really can't handle is (Moammar) Gadhafi of Libya.

Reagan as statesman lives by the adage "never paint your adversary into a corner." I didn't know that about him.

Q. What are some of the things that are left out of the diaries, some of the things you'd like to have known more about and don't find there?

A. I edited my condensed version so that the average Joe can read it like a book, from beginning to end, in a manageable-sized volume. But in 18 months I'm bringing out in three volumes the complete diaries, which will probably be in a boxed set. That will be annotated more heavily and with a larger glossary and will be the definitive diaries.

Q. I was really wondering if there are things that Reagan doesn't address in his diaries that you would like to have seen addressed?

A. He left behind so much writing for a president that it's hard to quibble if something is not there. The truth is I had the opposite problem — so much material, and it's very hard to edit a president who's writing while in power. This is real-time prose. I had to make some severe cuts on domestic and energy policy, for example, just because there wasn't room. I favored Reagan and foreign policy in this volume.

Q. What does his prose style reveal about Reagan the man?

A. Mrs. Reagan is very clear he kept this diary for his own edification. He did not maintain a diary when he was governor of California and regretted he didn't. So when he beat Jimmy Carter in 1980 he decided to keep a diary as president, for himself.

There's no attempt here at literary flair or trying to be a master wordsmith. He's not Thomas Jefferson or Theodore Roosevelt. On the other hand, it takes a lot of self-discipline to maintain a diary like this. His prose is unadorned, straightforward and in some cases self-deprecating. And it works. You don't get annoyed at him. You never feel he's adding icing on the cake. You start trusting the diaries.

Q. As a contribution to the history of the American presidency, how important are these diaries?

A. It's incalculable how important they are for anyone wanting to study Cold War history. You can't really write about the Reagan years without footnoting these diaries, because it's really what Reagan is thinking at the time he's thinking it. In that regard it's a major primary source.

Q. Did he have any inkling the Soviet empire would collapse when it did and as precipitously as it did?

A. A couple of things struck me. How quickly he focused on squaring off with the Soviet Union. He witnessed three Soviet leaders die, and then Gorbachev appears on the horizon. He was slow to realize Gorbachev was this progenitor of change. He still viewed the Soviet Union with great suspicion.

But Reagan was always worried about Armageddon. This comes out of his religious beliefs, which are in the diary. He's terrified about war in the Middle East and a nuclear holocaust with the Soviet Union. So he decides in his presidency to address those two issues very carefully.

It's one of the reasons I believe he pulled the Marines out of Lebanon in 1983, recognizing that he wasn't going to get stuck in a war in the Middle East. It's a reason he worked with people like James Baker and George Shultz to reduce nuclear weapons. On his watch, he achieved those two goals.

At the end of the diaries there's a fascinating [entry] where Margaret Thatcher comes to the United States and Reagan says, in his own way, that "Thatcher's telling everybody I'm the guy who changed the world." Reagan was too humble to claim that himself, but by writing what Thatcher said he shows he had a recognition that he was an extremely important president.

There is no indication that he knew the Berlin Wall was going to come down a year after he left office or the Soviet Union would collapse a couple of years later. But he did recognize that he had changed the world, that he was more than a custodian president. That he would have a significant place in the annals of history.